Vacuum-insulated glass (VIG) windows typically include two or more glass panes with an evacuated space (i.e., vacuum) located between the panes. The overall construction provides improved thermal and noise insulating properties compared to ordinary glass windows. To prevent sagging and contact between adjacent glass panes, discrete spacers can be placed between adjacent glass panes. The spacers can be made of aluminum, plastic, ceramic, or glass and are conventionally distinct from the glass panes, i.e., they are separate, discrete elements disposed and fixed between the glass panes.
While conventional spacers are effective in separating the panes, they tend to be visible when looking through the window, thereby making the window unsightly. Moreover, in vacuum-insulated glass windows that comprise low emissivity coatings, conventional spacers can abrade the low-E coating, particularly when exposed to a thermal gradient where differential thermal expansion between the indoor and out door panes can cause relative movement of the glass panes and the spacers. Abraded or otherwise damaged low-E coatings non-uniformly reflect incident light, which manifests as so-called “starlight emission” which is an undesired optical effect in window glass. In addition, the need to dispose the discrete spacers between the panes and then fix the spacers to the panes adds cost and complexity to the VIG window manufacturing process.
In view of the foregoing, there is a need for economical low-E vacuum-insulated glass windows as well as the attendant methods for making such windows.